Monitoring induced gene expression of single cells in a multilayer microchip

We present a microfluidic system that facilitates long-term measurements of single cell response to external stimuli. The difficulty of addressing cells individually was overcome by using a two-layer microfluidic device. The top layer is designed for trapping and culturing of cells while the bottom layer is employed for supplying chemical compounds that can be transported towards the cells in defined concentrations and temporal sequences. A porous polyester membrane that supports transport and diffusion of compounds from below separates the microchannels of both layers. The performance and potential of the device are demonstrated using human embryonic kidney cells (HEK293) transfected with an inducible gene expression system. Expression of a fluorescent protein (ZsGreen1-DR) is observed while varying the concentration and exposure time of the inducer tetracycline. The study reveals the heterogeneous response of the cells as well as average responses of tens of cells that are analyzed in parallel. The microfluidic platform enables systematic studies under defined conditions and is a valuable tool for general single cell studies to obtain insights into mechanisms and kinetics that are not accessible by conventional macroscopic methods. Figure A two-layer microfluidic device is presented that facilitates measurements of single cell response to external stimul

Conjoint Behavioral Consultation: Application to the School-based Treatment of Anxiety Disorders

In the current paper we discuss the treatment of childhood anxiety disorders using a problem-solving consultation framework. The role of consultation as a service delivery model in a school setting is elaborated on, as well as the contribution that consultation has in the movement towards evidence-based practices in school psychology. Additionally, a description of the role of consultation specifically in the treatment of childhood anxiety is provided. The role of parents and teachers in treatment is further elucidated, and the separate influence each may have on traditional treatment outcomes is presented. Finally, we discuss the benefits of using a conjoint behavioral consultation model (CBC) of treatment, whereby a mental health professional consults with a child\u27s parents and teachers, who collaborate to assess, monitor, and treat the child\u27s problems. We conclude with a discussion of the benefits of this collaborative approach to treatment of childhood anxiety and illustrate the application of CBC with a case example of selective mutism

Catalysts of Women’s Success in Academic STEM: A Feminist Poststructural Discourse Analysis

This qualitative study seeks understand the phenomena that activate women’s success in STEM disciplines where women’s representation has not yet attained critical mass. A poststructuralist emphasis on complexity and changing nature of power relations offers a framework that illuminates the ways in which elite academic women navigate social inequalities, hierarchies of power, and non-democratic practices. Feminist poststructural discourse analysis (FPDA) draws from the women’s experiences to better understand their complex, shifting positions. Eight female tenured full professors of STEM at research-focused universities in the United States participated in the study. Data sources were in-depth semi-structured interviews, a demographic survey, and curricula vitae. Findings will help shape programs and policies aimed at increasing female representation and promoting achievement at senior levels in academic STEM fields

The azimuth structure of nuclear collisions -- I

We describe azimuth structure commonly associated with elliptic and directed flow in the context of 2D angular autocorrelations for the purpose of precise separation of so-called nonflow (mainly minijets) from flow. We extend the Fourier-transform description of azimuth structure to include power spectra and autocorrelations related by the Wiener-Khintchine theorem. We analyze several examples of conventional flow analysis in that context and question the relevance of reaction plane estimation to flow analysis. We introduce the 2D angular autocorrelation with examples from data analysis and describe a simulation exercise which demonstrates precise separation of flow and nonflow using the 2D autocorrelation method. We show that an alternative correlation measure based on Pearson's normalized covariance provides a more intuitive measure of azimuth structure.Comment: 27 pages, 12 figure

Temporal dynamics of Prochlorococcus ecotypes in the Atlantic and Pacific oceans

To better understand the temporal and spatial dynamics of Prochlorococcus populations, and how these populations co-vary with the physical environment, we followed monthly changes in the abundance of five ecotypes—two high-light adapted and three low-light adapted—over a 5-year period in coordination with the Bermuda Atlantic Time Series (BATS) and Hawaii Ocean Time-series (HOT) programs. Ecotype abundance displayed weak seasonal fluctuations at HOT and strong seasonal fluctuations at BATS. Furthermore, stable ‘layered’ depth distributions, where different Prochlorococcus ecotypes reached maximum abundance at different depths, were maintained consistently for 5 years at HOT. Layered distributions were also observed at BATS, although winter deep mixing events disrupted these patterns each year and produced large variations in ecotype abundance. Interestingly, the layered ecotype distributions were regularly reestablished each year after deep mixing subsided at BATS. In addition, Prochlorococcus ecotypes each responded differently to the strong seasonal changes in light, temperature and mixing at BATS, resulting in a reproducible annual succession of ecotype blooms. Patterns of ecotype abundance, in combination with physiological assays of cultured isolates, confirmed that the low-light adapted eNATL could be distinguished from other low-light adapted ecotypes based on its ability to withstand temporary exposure to high-intensity light, a characteristic stress of the surface mixed layer. Finally, total Prochlorococcus and Synechococcus dynamics were compared with similar time series data collected a decade earlier at each location. The two data sets were remarkably similar—testimony to the resilience of these complex dynamic systems on decadal time scales.National Science Foundation (U.S.)Gordon and Betty Moore Foundatio

Sensitive species and natural communities known to occur on the Picket Wire Canyonlands, Comanche National Grassland, Colorado

November 15, 1995.Christopher A. Pague ... [et al.]